Operation High Speed Slab Caster for Hot Direct Rolling

The slab caster No.5 was put into operation in September, 1984 at NKK Fukuyama Works, which was directly connected with the hot strip mill No.2 for the purpose of Hot Direct Rolling Process (HDR). To realize the HDR this caster is provided with various automatic facilities and with several characteristics on operation such as mentioned below. (1) For high speed casting (over 2.0 m/min); low viscosity mold powder (lithium being added), nonsinusoidal oscillation, and mold copper plate, etc. (2) For high temperature slab discharging; heat insulating apparatus, secondary cooling with width control system, and slab edge heater. (3) For improvement of surface and inner quality of slab; accurate mold level control, optimum design of immersion nozzle, air mist cooling, etc. By these newly developed techniques the monthly production by the HDR process was increased up to 100 thousand tons of steel. This report describes the new facilities and the operation technologies developed for this HDR process.